42 = -6 + 3x
42 = 3x - 6 (just moving 3x and -6 around)
42+ 6 = 3x - 6 + 6 (adding 6 to both sides)
42 = 3x
42/3 = 3x/3 (dividing by 3 to both sides to isolate for x)
14 = x
You're trying to isolate for x, so you have to get it alone on one side. To do this you have to add/subtract and multiply/divide, but remember that whatever you do to one side you have to do to the other. Hope this helped! :)
